All of Fabio Cardoso, Evanilson, Otavio, Gabriel Veron and Francisco Meixedo occupy spots in the treatment room, while Galeno and Mateus Uribe are also unlikely to make the cut this week.
The Dragons' fitness woes were exacerbated in the weekend's Primeira Liga win over Rio Ave too, as Toni Martinez had to be withdrawn late on after scoring the only goal of the contest in the first half.
It is unclear how severe Martinez's problem is, but Danny Namaso may be required to partner Mehdi Taremi in attack - the Iranian struck five goals and two assists in the group stage to seal Porto's progress as group winners.
The visitors' depleted midfield should be manned by Marko Grujic and Stephen Eustaquio, and a first-ever Champions League appearance could come the way of Andre Franco on the right-hand side.
One Pepe should start on the left for Porto, and the attacker's namesake - 39-year-old defensive veteran Pepe - will likely line up from the first whistle too, partnering David Carmo in front of the in-demand Diogo Costa as Ivan Marcano drops to the bench.
Left-back Wendell has made a miraculous recovery from being stretchered off against Vizela two weeks ago, but Champions League regular Zaidu Sanusi should get the nod here, as Joao Mario occupies the right-back role.
Porto possible starting lineup: Costa; Mario, Pepe, Carmo, Sanusi; Franco, Eustaquio, Grujic, Pepe; Taremi, Namaso
Borussia Dortmund 
Real Madrid 
Atalanta 
Fiorentina 
Espanyol 
Cartagena 
Gibraltar 
Scotland 
Croatia 
North Macedonia 
Albania 
Liechtenstein 
England 
Bosnia & Herzegovina 
Germany 
Ukraine 
Slovenia 
Armenia 
Switzerland 
Estonia 
Romania 
Bulgaria 
Austria 
Serbia 
Portugal 
Finland 
Rep. Of Ireland 
Hungary 
Italy 
Turkey 
San Marino 
Slovakia 
Denmark 
Sweden 
Norway 
Kosovo 
Belgium 
Montenegro 
France 
Luxembourg 
Spain 
Andorra 
Wales 
Netherlands 
Canada 
Czech Republic 
Malta 
Kazakhstan 
Azerbaijan 
Belarus 
Russia 
Iceland 
Greece